In the past I would participate in the occasional town-wide hazardous waste days, which amounted to waiting in a long line of cars for hours then paying to dispose of whatever it was you had.
Recently, the Devens HHW (www.DevensHHW.com) opened, and having a shed full of used motor oil, anti-freeze, brake fluid, and a host of other unidentified gifts from the Nashua River, I went down there.
I had some correspondence with the director there, and fully expected an inconvenient experience. But when I arrived, I was greeted by the friendly staff, they inquired about what I had, and did all the work. I of course, asked whether they could cut me a break because a good deal of what I has was obviously from the river, but they're independently funded and had no such provisions.
I gladly paid to be rid of the materials (and have some space in my shed back) and I was off. But basically I paid someone else's disposal fee. It wasn't a fortune, my bill was $60, so about $30 would have been for the river stuff. I'd asked the Nashua River Watershed Association if they had any such programs to help volunteers, but sadly, no.
So here's a question for the readers. Would any corporations be willing to create a small fund for the disposal of waste pulled from rivers. I'm not quite sure how the whole thing would work, but perhaps the funds could be used at the discretion of the DevensHHW and other facilities. I might think a company like @CleanHarbors would be interested. Any takers?